Corrosion inhibition of mild steel by pentyltriphenylphosphoniumbromide in acid medium – Part-II
Authors/Creators
Description
Department of Chemistry, Shyam Lal College, University of Delhi, G. T. Road, Shahdara, Delhi-110 032, India
E-mail : drvinodsharma57@yahoo.com, arkajagoswami@gmail.com
Manuscript received online 03 August 2013, revised 25 November 2013, accepted 25 January 2014
The efficiency of pentyltriphenylphosphoniumbromide (PTPPB) as corrosion inhibitor for mild steel in H2SO4 (10–3 M, 10–5 M, 10–7 M) was investigated by electrochemical methods like study state galvanostatic and potentiostatic polarization measurements. The dissolution parameters such as corrosion current, passive current, flade potential, cathodic and anodic Tafel slopes and efficiencies were determined and studied at four different temperatures (298 K, 308 K, 318 K, 328 K). The optimum concentration of this compound for maximum inhibition efficiency was determined by galvanostatic method. PTPPB gave more than 93% inhibition in presence of 10–3 M H2SO4 at 298 K. Potentiodynamic polarization studies revealed that PTPPB is mixed inhibitor and good passivator in 1 N H2SO4 . According to temperature kinetics PTPPB obeyed Temkin’s and Freundlich adsorption isotherm, due to adsorption on metal surface. Certain quantum chemical parameters have been calculated to reinforce the electrochemical results.